Determination of traces of metals by anodic stripping voltammetry at a rotating glassy carbon ring-disc electrode : Part 2. Comparison between linear anodic stripping voltammetry with ring collection and various other stripping techniques

Abstract

Linear anodic stripping voltammetry (a.s.v.) with ring collection is compared with differential pulse a.s.v. at a hanging mercury drop electrode and with linear or differential pulse a.s.v. at a mercury film rotating electrode. Sensitivity, detection limits, resolution, base-line, the concentration range covered, the influence of organic compounds in the sample, and operational ease are discussed. The main conclusions are as follows: differential pulse a.s.v. at a hanging mercury drop electrode is best suited for determining heavy metal concentrations of the order of μ l -1; the differential pulse mode at the rotating disc electrode or the d.c. mode at the rotating ring-disc electrode are required for sub-μ l -1 concentrations; the limits of detection for the determination of cadmium, lead and copper are in the 2–5 ng l -1.